I. Field of the Invention
This invention relates to a reading apparatus which may be used to determine the orientation of postal material such as envelopes; namely to determine if the envelope is facing down, up, reverse or obverse.
II. Background of the Invention
In recent years, with the development of character reading apparatus, the sorting of postal material has become increasingly automated. Postal material as collected at a Post Office faces in all different directions. Before this material can be fed into a sorting machine the material must be sent through an alignment/stamping machine for aligning the direction in which the material faces.
Postal material from some countries has been standardized in various ways, but non-standardized material presents numerous problems. Conventional alignment/stamping machines for dealing with standardized postal materials detect airmail mark location, stamp location and/or envelope flap orientation, and determine the side of the material with the stamp and airmail mark to be the obverse and the side of the material with the envelope flap to be the reverse. Also, based on the position of the airmail mark and the stamp, the material may be determined to be upside down or right side up. Accurate detection of the airmail mark, stamp, envelope flap and the like is therefore crucial to accurate determination of the orientation of the postal material containing that airmail mark, stamp and envelope flap.
In general, in addition to the airmail marks, edge marks such as red and blue diagonal stripes located alternatingly at equal intervals around the edge of the envelope are used to indicate that postal material is airmail. The airmail marks used to determine postal material orientation, may be located to overlap the striped edge airmail marks. Stamp may also be located to at least partially overlap the edge marks. This overlapping of airmail marks and edge marks and of stamps and edge marks at times makes the airmail mark and the stamp impossible to distinguish from those edge marks and, therefore, impossible to detect.